package com.wc.AlgoOJ_train.train1.c0.A017;

import java.util.Scanner;

/**
 * @Author congge
 * @Date 2023/12/25 11:19
 * @description Max Num
 * http://43.138.190.70:8888/p/A017
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        while (n-- > 0) {
            int m = sc.nextInt();
            double maxH = -1;
            while (m-- > 0) {
                double h = sc.nextDouble();
                maxH = Math.max(h, maxH);
            }
            System.out.printf("%.2f\n",maxH);
        }
    }
}
